This invention relates to internal combustion engines. In certain embodiments, this invention relates to internal combustion engines with integrated linear electric generators. In certain other embodiments, this invention relates to internal combustion engines with integrated pumping means.
There are well-known systems that use internal combustion engines to produce electric power. One such electric power generating mechanism is a generator that links the reciprocating action of a piston to generate magnetic flux change. A linear generator is essentially a coil and a series of magnets. “Coil” is understood as the windings plus the laminated flux path. “Magnets” is understood as permanent or electromagnets. Relative movement of the coil through the magnetic field induces an electric current.
There are various types of opposed piston and opposed cylinder combustion engines and various internal combustion engines with electrical power generating mechanisms. Several representative examples are discussed herein.
One example is U.S. Pat. No. 5,850,111 issued Dec. 15, 1998, which is incorporated herein by reference in its entirety for all purposes. This patent discloses a free piston variable stroke linear alternator alternating current (AC) power generator for a combustion engine with opposed cylinders and one moving element per piston pair.
Another example is U.S. Pat. No. 5,654,596 issued Aug. 5, 1997, which is incorporated herein by reference in its entirety for all purposes. This reference discloses a linear electrodynamic machine that includes one mover assembly and one stator assembly.
U.S. Pat. No. 3,541,362 discloses an opposed piston engine with two pairs of pistons, a crankshaft, connecting rods and at least one series of inductors comprising field magnets and pole pieces. The connecting rods cause reciprocation of oppositely moving members.
Other disclosures, such as U.S. Pat. Nos. 5,397,922; 4,873,826; or 4,649,283, describe internal combustion engines with linear generators. The aforementioned prior art devices all have one or more limitations. For example, they have undue complexity and quantity of the moving elements, such as crankshafts and wrist pins, and are thus not free-piston engines. Further, such prior art references do not have oppositely moving reciprocating mass elements so that the engines and associated electrical power generating mechanisms operate at a reduced level of vibration and efficiency. The prior art devices are also disadvantageous in that they may be heavy and noisy. Still further, existing systems may have low operating efficiencies and significant frictional losses. Additionally, dynamic imbalance in the existing systems results in extra wear on the reciprocating and related moving components.
An improvement to many of the shortcomings in the prior art, is disclosed in U.S. Pat. No. 6,170,443, which was invented by a common inventor and is under common ownership with this application, is incorporated herein by reference in its entirety for all purposes. The '443 patent discloses an internal combustion engine that has opposed cylinders, each with a pair of opposed pistons connected to a crankshaft with connecting rods, such as pushrods and pullrods. This system does not include electric power generating mechanisms. Also, this patent does not disclose a free-piston opposed piston opposed cylinder engine having three cylinders.